Iso-grid composite component

ABSTRACT

An iso-grid composite component according to an exemplary aspect of the present disclosure includes a spacer transverse to a uni-tape ply bundle, the spacer interrupted by the uni-tape ply bundle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/753,071, filed Jun. 29, 2015, which is a divisional of U.S. patentapplication Ser. No. 12/892,014, filed Sep. 28, 2010 and issued as U.S.Pat. No. 9,126,374 on Sep. 8, 2015.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This disclosure was made with Government support under N00019-02-C-3003awarded by The United States Air Force. The Government has certainrights in this invention.

BACKGROUND

The present disclosure relates to an iso-grid composite component andmore particularly to gas turbine engines having convergent/divergentnozzles with iso-grid composite components.

A variable area exhaust nozzle optimizes the thrust produced within agas turbine engine. In augmented gas turbine engines,convergent/divergent (C/D) nozzles provide a multitude of nozzlepositions. The term “convergent-divergent” describes an exhaust nozzlehaving a convergent section upstream of a divergent section. Exhaustgases exiting the turbine section pass through the decreasing diameterconvergent section before passing through the increasing diameterdivergent section.

The convergent section is pivotally connected to an exhaust ductstructure and to the divergent section. The divergent section ispivotally connected to the convergent section and to an external fairingpositioned radially outboard of the divergent section. The upstream endof the external fairing is pivotally attached to an outer staticstructure to provide an outer aerodynamic surface for the C/D. Theconvergent, divergent, and external fairing sections generally includeflaps and seals to accommodate changes in the nozzle variable orificearea and axis skew (if the nozzle is vectorable) by sliding relative toand overlapping each other as the orifice area decreases or increases.

The flaps and seals are often manufactured of carbon fiber compositeswhich incorporate either monocoque constructions (consistent thicknesspart) or hollow rib reinforcements. Although effective, these techniquesmay require significant weight or design space.

SUMMARY

An iso-grid composite component according to an exemplary aspect of thepresent disclosure includes a spacer transverse to a uni-tape plybundle, the spacer interrupted by the uni-tape ply bundle.

An iso-grid composite component according to an exemplary aspect of thepresent disclosure includes a multiple of uni-tape ply bundles, each ofthe multiple of uni-tape ply bundles at different levels within a ribpattern such that each uni-tape ply bundle within a level of a first ribof the rib pattern is uninterrupted by a spacer which at least partiallydefines a second rib of the rib pattern transverse to the first rib atthe respective level.

A method of defining a rib structure within an iso-grid compositecomponent according to an exemplary aspect of the present disclosureincludes defining a first rib at least partially with a uni-tape plybundle at a first level and defining a second rib transverse to thefirst rib at least partially with a spacer at the first level, thespacer interrupted by the uni-tape ply bundle.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features will become apparent to those skilled in the art fromthe following detailed description of the disclosed non-limitingembodiment. The drawings that accompany the detailed description can bebriefly described as follows:

FIG. 1 is a general perspective view of a variable geometry C/D exhaustnozzle of the present invention with the nozzle shown in a minimumdilated position;

FIG. 2 is a general partial sectional side view of a variable geometryC/D exhaust nozzle of the present invention with the nozzle shown in aminimum dilated position which corresponds with FIG. 1;

FIG. 3 is an outer perspective view of an external flap manufactured ofcomposite materials in an iso-grid construction according to the presentdisclosure;

FIG. 4 is an inner perspective view of the external flap of FIG. 3manufactured of composite materials in an iso-grid constructionaccording to the present disclosure;

FIG. 5 is an inner perspective view of the external flap illustrating amultiple of lateral ribs and longitudinal ribs formed from a multiple ofuni-tape ply bundles and spacers in which only the spacers areinterrupted, the iso-grid construction shown without interstitial plylayer between each level of the multiple of uni-tape ply bundles andspacers;

FIG. 6 is an exploded view of the layup which provides a multiple ofuni-tape ply bundles and spacer levels which define the ribs and theinterstitial ply layers which separate the multiple of uni-tape plybundles and spacer levels; and

FIG. 7 is an exploded view of a single uni-tape ply bundle.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates a convergent/divergent (C/D) nozzlesystem 20 for a gas turbine engine. The nozzle system 20 is movablebetween a minimal dilated position (FIG. 1), which is typical duringnon-afterburning operation and a maximum dilated position (not shown),which is typical during afterburning operation.

The nozzle system 20 generally includes a plurality of circumferentiallydistributed convergent flaps 22, each pivotably connected to a nozzlestatic structure 24. A plurality of circumferentially distributeddivergent flaps 28 are pivotably connected through a joint structure 30to adjust an aft end section of each convergent flap 22. A plurality ofconvergent seals 32 are each pivotally connected to a respectivedivergent seal 34 which are respectively distributed circumferentiallybetween each divergent flap 28 and convergent flap 28 sets. Eachconvergent seal 32 is pivotably connected to the static structure 24with each divergent seal 34 pivotably connected through a jointstructure 36 adjacent an aft end section of each convergent seal 32. Theconvergent and divergent flaps 22, 28 and the convergent and divergentseals 32, 34, taken collectively, define the radial outer boundary of acombustion gas path F to define a convergent section 38 and a divergentsection 40 with a throat area 42 defined therebetween (FIG. 2).

With reference to FIG. 2, an outer aerodynamic surface of the nozzlesystem 20 is defined by a plurality of external flaps 50 (FIGS. 3 and4). Each of the plurality of external flaps 50 pivot relative arespective divergent flap 28 about a pivot axis 52 defined by anexternal flap hinge 54 (FIG. 4). Each of the plurality of external flaps50 also slide relative the nozzle static structure 24 through track arms56 (FIG. 4). The plurality of external flaps 50, taken collectively,define an outer aerodynamic surface of the nozzle system 20 andaccommodate movement between the maximum dilated position and theminimal dilated position through sliding movement relative the staticstructure 24 and overlapping movement between adjacent external flaps50.

With reference to FIG. 5, each external flap 50 includes an iso-gridconstruction (FIG. 6) that alternatively interrupts the internal loadpaths within a multiple of lateral ribs 60 and longitudinal ribs 62 soas to prevent an internal thermal fight which would heretofor causeinternal dissolution of the component. In one non-limiting embodiment,the external flap 50 includes four longitudinal ribs 62-1-62-4 and fivelateral ribs 60-1-60-5. It should be understood that the particular ribarrangement is related to the desired shape of the component such as theexternal flap 50. Although the iso-grid construction is illustratedherein with regards to an external flap 50 in accords with onenon-limiting embodiment, it should be realized that any compositeiso-grid structure will benefit herefrom. It should also be understoodthat although relatively rectilinear iso-grid geometry is illustrated,other geometries are usable herewith.

With reference to FIG. 6, the multiple of lateral ribs 60 andlongitudinal ribs 62 of the iso-grid construction are formed from amultiple of uni-tape ply bundles 70 and spacers 72 in which only thespacers 72 are interrupted. In one non-limiting embodiment, eachuni-tape ply bundle 70 is a buildup of four (4) uni-tape plies 74-1;74-2; 74-3; 74-4 and one spacer ply 76 such that the spacer ply 76separates two (2) uni-tape plies 74-1; 74-2 from two (2) uni-tape plies74-3; 74-4 (FIG. 7). Two (2) uni-tape plies 74 are generally of anequivalent height to one spacer ply 76 such that one (1) uni-tape plybundle 70 is of an approximate equivalent height to three (3) spacerplies 76 within each of the ribs 60, 62. Generally, no more than 4uni-tape plies are located adjacent to each other and the middle spacerply 76 of the uni-tape ply bundle 70 may be oriented at a 45° directionto the associated uni-tape ply 74 direction.

The iso-grid composite component construction makes use of the higherstrength uni-tape plies 74 to build up strong and low weight internalribs 60, 62. Internal thermal fights between transverse uni-tape plies74 are avoided by selectively alternating each uni-tape ply bundle 70 atdifferent heights within the rib pattern such that when oneun-interrupted uni-tape ply bundle 70 is within one level of thelongitudinal rib 62, the lateral rib 60 transverse thereto is defined bya spacer 72 which is interrupted at that level. At an adjacent level,the uni-tape ply bundle 70 runs un-interrupted within the lateral rib 60while the longitudinal rib 62 at the same level includes the interruptedspacer 72. That is, each uni-tape ply bundle 70 runs un-interruptedregardless of the level or direction for that particular uni-tape plybundle 70. It should be understood that any number of levels may beprovided to build up the particular iso-grid component such as thedisclosed external flap 50.

In addition, each level of uni-tape ply bundles 70 and spacers 72 whichform the multiple of lateral ribs 60 and longitudinal ribs 62 may beseparated by an interstitial ply layer 80. Each interstitial ply layer80 may itself be a layup of any number of spacer plies such as fabricplies which are arranged at particular relative angular orientations. Itshould be understood that any number of such plies may be so utilizedbetween the multiple of lateral ribs 60 and longitudinal ribs 62.

The uni-tape ply bundles 70 are uninterrupted and the spacers 72 areutilized to equalize height such that the uni-tape ply bundles 70 withinthe lateral ribs 60 and longitudinal ribs 62 do not directly overlap toform uni-tape ply “bumps” at intersections between the lateral ribs 60and longitudinal ribs 62. That is, transverse uni-tape ply bundles 70are separated and spaced by the spacers 72 so that a constant height ismaintained as Applicant has determined that such “bumps” may result indelamination regions since uni-tape has an inherent difference inthermal growth along the fiber direction as compared to across the fiberdirection. Typical differences in this thermal growth approach 20 timessuch that the thermal expansion at a “bump” in conventional rib layupsin which uni-tape directly overlaps and forms a “bump” may often resultin delaminating and potential internally generated destruction of thelayup. Moreover, Applicant has determined that the spacers 72 cushionand accommodate the thermal expansion which results in a robust butrelatively light weight component.

The iso-grid construction is lighter than monocoque constructions asuni-tape fibers can be placed to selectively follow the load paths. Theiso-grid construction is also considerably more compact in the thicknessdirection than top hat hollow rib construction which facilitates usagein confined regions such as C/D nozzles as well as various othercomponents.

It should be understood that like reference numerals identifycorresponding or similar elements throughout the several drawings. Itshould also be understood that although a particular componentarrangement is disclosed in the illustrated embodiment, otherarrangements will benefit herefrom.

Although particular step sequences are shown, described, and claimed, itshould be understood that steps may be performed in any order, separatedor combined unless otherwise indicated and will still benefit from thepresent disclosure.

The foregoing description is exemplary rather than defined by thelimitations within. Various non-limiting embodiments are disclosedherein, however, one of ordinary skill in the art would recognize thatvarious modifications and variations in light of the above teachingswill fall within the scope of the appended claims. It is therefore to beunderstood that within the scope of the appended claims, the disclosuremay be practiced other than as specifically described. For that reasonthe appended claims should be studied to determine true scope andcontent.

What is claimed is:
 1. An iso-grid composite component for a gas turbineengine comprising: a uni-tape ply bundle including uni-tape plies and afirst spacer ply; a spacer including a second, different spacer ply,said spacer transverse to said uni-tape ply bundle, and said spacerinterrupted by said uni-tape ply bundle; an interstitial ply layeradjacent said uni-tape ply bundle and said spacer; and wherein saiduni-tape ply bundle and said spacer define a rib pattern, said uni-tapeply bundle at least partially defines a first rib of said rib pattern,said spacer at least partially defines a second rib of said rib patternthat is transverse to said first rib, and said interstitial ply spanningbetween a first sidewall of said first rib and a second sidewall of saidsecond rib.
 2. The iso-grid composite component as recited in claim 1,wherein said uni-tape ply bundle is a buildup of said uni-tape plies andsaid first spacer ply such that said first spacer ply separates saiduni-tape plies.
 3. The iso-grid composite component as recited in claim2, wherein each of said uni-tape plies includes a first material, saidfirst spacer ply includes a second material that is different from thefirst material in fiber construction.
 4. The iso-grid compositecomponent as recited in claim 3, wherein each of said uni-tape pliesdefines a first height, and said first spacer ply defines a secondheight different from said first height.
 5. The iso-grid compositecomponent as recited in claim 4, wherein said second spacer ply includessaid second material.
 6. The iso-grid composite component as recited inclaim 5, wherein said second spacer ply defines a third height differentfrom said first height.
 7. The iso-grid composite component as recitedin claim 6, wherein said interstitial ply layer includes a thirdmaterial different in fiber construction from said first material. 8.The iso-grid composite component as recited in claim 7, wherein saidfiber construction of said first material is uni-directional, and saidfiber construction of said third material is fabric.
 9. The iso-gridcomposite component as recited in claim 7, further comprising a secondspacer and a second uni-tape ply bundle adjacent said interstitial plylayer, said second spacer at least partially defines said first rib andsaid second uni-tape ply bundle at least partially defines said secondrib.
 10. The iso-grid composite component as recited in claim 9, whereinsaid uni-tape ply bundle and said spacer are of approximately equalheight.
 11. The iso-grid composite component as recited in claim 10,wherein said uni-tape ply bundle is a buildup of four (4) of saiduni-tape plies and one (1) of said first spacer ply such that said firstspacer ply separates two (2) of said uni-tape plies from two (2) otherof said uni-tape plies.
 12. The iso-grid composite component as recitedin claim 11, wherein said spacer is a buildup of three (3) of saidsecond spacer plies.
 13. The iso-grid composite component as recited inclaim 12, wherein said fiber construction of said second material isfabric.
 14. An iso-grid composite component for a gas turbine enginecomprising: a multiple of uni-tape ply bundles, each of said uni-tapeply bundles includes uni-tape plies and a first spacer ply; a multipleof spacers, each of said multiple of uni-tape ply bundles at differentlevels within a rib pattern such that each uni-tape ply bundle within alevel of a first rib of said rib pattern is uninterrupted by at leastone of said multiple of spacers which at least partially defines asecond rib of said rib pattern transverse to said first rib at saidrespective level; a multiple of interstitial ply layers, each one ofsaid multiple of interstitial ply layers being adjacent to a respectivelevel of said multiple of uni-tape ply bundles and said multiple ofspacers within said respective level; and wherein said first rib andsaid second rib of said rib pattern define a space at each of saidrespective levels, said space extending at least partially between saidrespective levels, said space being free of said multiple of uni-tapeply bundles and said multiple of spacers, and said interstitial ply atleast partially disposed within said space.
 15. The iso-grid compositecomponent as recited in claim 14, wherein each of said multiple ofuni-tape ply bundles and said multiple of spacers are of approximatelyequal height within said respective level.
 16. The iso-grid compositecomponent as recited in claim 15, wherein: each of said uni-tape pliesdefines a first height, said first spacer ply defines a second heightdifferent from said first height; and each of said a multiple of spacersincludes a second spacer ply, said second spacer ply defining a thirdheight different from said first height.
 17. The iso-grid compositecomponent as recited in claim 14, wherein each of said uni-tape pliesincludes a first material and said first spacer ply includes a secondmaterial that is different from the first material in fiberconstruction, and said interstitial ply layer includes a third materialdifferent in fiber construction from said first material.
 18. Theiso-grid composite component as recited in claim 17, wherein each ofsaid multiple of uni-tape ply bundles and said multiple of spacers areof approximately equal height within said respective level.
 19. Theiso-grid composite component as recited in claim 18, wherein: each ofsaid uni-tape plies defines a first height, said first spacer plydefines a second height different from said first height; each of said amultiple of spacers includes a second spacer ply, said second spacer plydefining a third height different from said first height; and each saidspacer ply also including said second material.
 20. The iso-gridcomposite component as recited in claim 19, wherein said iso-gridcomposite component is an external flap of a nozzle system.